It has been shown that crossing the midline affects the performance of fine motor skills but the underlying mechanisms are not well understood. This issue is particularly important with respect to the development of motor activities such as writing or pointing in children. Forty-eight right-handed children performed goal-directed movements toward targets positioned either at the midline, or in the left (contralateral side), or right (ipsilateral) hemispace. Findings revealed that movements were more accurate in ipsilateral than in contralateral space and their overall accuracy increased by 42% between 6 and 10 years of age. Differences in movement time among hemispaces depended on the joints predominantly involved in producing the movements (wrist versus fingers). Lower accuracy of movements in contralateral workspace is also present when participants do not have to cross the midline but only move within this workspace. In motor proficient children, no developmental trends were found for these hemispace effects.
Bouwien C. M. Smits-Engelsman, Stephan P. Swinnen and Jacques Duysens
Hilde Van Waelvelde, Willy De Weerdt, Paul De Cock, Bouwien C.M. Smits-Engelsman and Wim Peersman
The aim of this study was to compare the quality of ball catching performance of children with DCD to the performance of younger typically developing children. The outcome measures used were a modified ball catching item of the Test of Gross Motor Development and the number of grasping errors in a ball catching test. In the study, children with DCD were matched with younger typically developing children according to gender and the number of caught balls in the ball catching test. Children with DCD made significantly more grasping errors and scored significantly lower on the modified TGMD-item. Children with DCD were not only delayed in ball catching but they also seemed to use different movement strategies compared to younger typically developing children.
Hilde Van Waelvelde, Wim Peersman, Mattieu Lenoir and Bouwien C.M. Smits Engelsman
The aim of this study was to investigate the convergent validity of the Movement Assessment Battery for Children (M-ABC) and the Peabody Developmental Motor Scales – 2 (PDMS-2). Thirty-one 4- and 5-year-old children (mean age 4 years 11 months, SD 6 months), all recruited from a clinical setting, took part in the study. Children were tested on the M-ABC and the PDMS-2 in a counterbalanced order on the same occasion. The results showed that the total scores on the two tests correlated well (rs = .76). However, when the ability of the two tests to identify children with difficulties was examined, agreement between them was low (K = .29), with the PDMS-2 being less sensitive to mild motor impairment in this population. Taken together, these findings suggest that clinicians need to be aware that, although measuring a similar construct, these tests are not interchangeable.
Bouwien C.M. Smits-Engelsman, Gerard P. Van Galen and Jacques Duysens
Ninety-four participants (age 5–93 years) performed isometric force production tasks at five different levels of their maximum voluntary contraction (MVC) with either one or two index fingers. Research questions were whether variability measures in the bimanual task condition were different compared to the unimanual condition and whether this difference showed a developmental trend. Results showed that force regulation was more demanding during bimanual tasks (33% increase in error). During development signal-to-noise ratio (SNR) increased threefold from 5–12 years of age and again 60% from 12 years to adulthood. SNR for the elderly was comparable to values of 9 to 10-year-olds. SNR decreased in the bimanual task, particularly for the older persons. For adults and elderly, optimal SNR levels were observed around 36% of their MVC. In younger children, however, the inverted U-shape in the SNR over the full range of forces was not yet present.
Arturo Forner-Cordero, Virgínia H. Quadrado, Sitsofe A. Tsagbey and Bouwien C.M. Smits-Engelsman
The present study analyzes the learning in a coincident timing task with force perturbation. We aimed to verify whether a predictable load (constant spring) applied to hand movements could facilitate learning and, thus, performance improvement with respect to movements without any external load and an unpredictable load to perform a coincident timing task with a few number of repetitions (n = 28) under acquisition and transfer phases. The results showed that the group with a predictable load had a significant better performance with lower percentage of errors and smaller time variance in the acquisition and transfer phase. The groups with no load and unpredictable load had a similar performance in the transfer phase. It can be concluded that adding a predictable force to the coincident timing task results in performance improvement. Therefore, learning to reach a target at a correct time could be improved with the application of predictable external loads.